1. Field of the Invention
Embodiments of the present disclosure relate generally to a system, a device and a method for sustained medical infusion of fluids and/or continuous monitoring of body analyte. In some embodiments, a portable infusion patch-like device is provided that is securable (e.g., adherable) to the skin and that optionally may also continuously and/or periodically monitor body analytes. In some embodiments, a multi-component fluid dispensing and/or bodily analytes monitoring device is described that includes one or more vents configured to, for example, direct air to, among other things, balance pressure differences between the pressure within and outside its interior by enabling air transfer through the device while preventing entrance of water and other liquids which could affect functioning of the device.
2. Background of Invention
Medical treatment of several illnesses requires, under some circumstances, continuous or periodical drug infusion into various body compartments, such as subcutaneous and intra-venous injections. For example, diabetes mellitus patients require the administration of varying amounts of insulin throughout the day to control their blood glucose levels. In recent years, ambulatory portable insulin infusion pumps have emerged as a superior alternative to multiple daily injections of insulin by syringe. These pumps, which deliver insulin at continuous basal rates as well as in bolus volumes, were developed to liberate patients from repeated self-administered injections, and to allow them to maintain a near-normal daily routine. In another example, ambulatory pumps may be used to treat post surgery pain where the treatment regiment requires relief by continuous or periodic administration of medication (e.g., administration of opium derivatives). These drugs can be locally delivered to the subcutaneous tissue surrounding the incision scar while avoiding systemic side effects of oral or intravenous administered analgesics. Another application of ambulatory pumps includes use of the pumps in the treatment of cancer patients that require continuous/periodical delivery of chemotherapy medications via an open vein access port.
Several ambulatory insulin infusion devices are available on the market. The first generation of such devices included disposable syringe-type reservoir, piston and tubes, as described, for example, in U.S. Pat. Nos. 3,631,847, 3,771,694, 4,657,486 and 4,544,369, the contents of all of which are hereby incorporated by reference in their entireties.
A drawback of these devices is their relatively large sizes and weights, resulting by their physical configuration and the relatively large driving mechanisms, e.g., syringes and pistons. These relatively bulky devices have to be carried in patients' pockets or be attached to the patients' belts. Consequently, the fluid delivery tubes of those devices are relatively long, usually longer than 60 cm, to enable needle insertion in remote sites of the body. Such uncomfortable bulky fluid delivery devices each having a relatively long tube are disfavored by the majority of diabetic insulin users because these devices interfere with the patients' regular activities, such as sleeping, exercising, etc.
To avoid tubing limitations, a second generation of pumps has been developed. Second generation pumps include a housing having a bottom surface adapted for attachment to the user's skin, a reservoir disposed within the housing, and an injection needle adapted for fluid communication with the reservoir. These skin securable (e.g., adhereable) devices are generally discarded every 2-3 days, much like the infusion sets employed in first generation pumps. Second generation devices are described, for example, in U.S. Pat. Nos. 5,957,895, 6,589,229 and 6,740,059, the contents of all of which are hereby incorporated by reference in their entireties. Other configurations of skin securable pumps are disclosed, for example, in U.S. Pat. Nos. 6,723,072 and 6,485,461, the contents of all of which are hereby incorporated by reference in their entireties. These patents describe, for example, a pump implemented as a single piece and remains secured to a user's skin for the entire usage duration. The needle emerges from the bottom surface of the device and is secured to the device housing. A drawback of these 2nd generation devices is their relative bulkiness and their high cost of manufacture. Particularly, the reservoirs used in conjunctions with these devices are typically tubular and syringe-like, thus requiring a relatively large occupying space and relatively large physical dimensions (e.g., large thickness). Another drawback of second generation devices is that users have to discard the entire device, including expensive electronics and the driving mechanisms of the devices, every 2-3 days.
To avoid, for example, volume and cost constraints, 3rd generation skin-secured devices have been proposed, as described, for example, in commonly-owned patent applications PCT/IL06/001276 and U.S. Ser. No. 11/397,115, filed Apr. 3, 2006, the contents of which are hereby incorporated by reference in their entireties. The device disclosed in these applications includes, in some embodiments, one or more of the following units:                1. A dispensing patch unit (hereinafter “dispensing patch”, “patch” or “dispensing device”) the dispensing patch unit generally includes two parts, a disposable part and a reusable part. The reusable part comprises, for example, electronic components, including a motor, a buzzer and a controller. The electronic components are configured to control and monitor, for example, the activity of the dispensing patch. The buzzer is configured, for example, to alarm the user under certain circumstances (e.g., when the reservoir has been emptied). The disposable part comprises, for example, a reservoir for therapeutic fluid, a short delivery tube, an outlet port and an energy source (e.g., battery). In some embodiments, switches/buttons may be provided on the dispensing patch to allow for delivery of doses in response to manual commands. After connection of the reusable and disposable parts, the assembled device may form a sealed item that has a relatively thin dimension, thus rendering the whole device inexpensive, light and discrete.        2. A remote control unit, which can be used for data acquisition, programming, and communication of user inputs.        3. A cradle unit—a skin securable (e.g., adherable) structure that is attached to the skin and enables connection and disconnection of the dispensing patch unit.        4. A cannula cartridge—a unit that includes a cannula for delivering a therapeutic fluid into the patient body.        
The dispensing patch unit may be attached to the body of a diabetic patient during the entire usage duration to achieve improved glycemic control. The two-part patch unit may be water tight to enable showering, swimming, and exposure to rain, food (e.g., soup) and beverages (e.g., beer, soda or coffee) that may unintentionally contaminate the device. Such two-part devices are described, for example, in co-owned U.S. Ser. No. 11/397,115 and in U.S. Provisional Application Ser. No. 60/922,794, entitled “Apparatus and method for pumping fluid into a mammal's body”, filed Apr. 10, 2007, the contents of all which are hereby incorporated by reference in their entireties.
In some embodiments, a dispensing patch unit that includes a continuous analyte monitor (to enable insulin dispensing and glucose monitoring) may be used. Such a patch unit is described in commonly-owned pending U.S. patent application Ser. No. 11/706,606, filed Feb. 14, 2007, U.S. Provisional Application No. 60/842,869, filed Sep. 6, 2006 and 60/848,511, filed Sep. 29, 2006, the contents of all which are hereby incorporated by reference in their entireties. Such a dual-function patch unit may also be composed of two parts and may be controlled remotely or manually. Such a patch unit may be water tight as well.